PDCP Feedback for Wireless Data Retransmission
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Solution Overview
Problem
Current wireless communication systems face challenges in accurately determining and retransmitting out-of-order data packets due to the lack of comprehensive feedback mechanisms, leading to inefficiencies in data delivery and increased latency.
Innovation Solution
The method involves receiving feedback data with a highest delivered PDCP sequence number and information about the range of successfully delivered data from a second network element, allowing the first network element to retransmit only the necessary data in the correct order, using techniques such as NR-U PDU and PDCP SN encapsulation within NR-U PDU, and deleting successfully delivered data from memory.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If comprehensive feedback mechanisms are implemented to track delivered packets, then data delivery reliability is improved, but device complexity and processing overhead increase
Solution Approach 1:
The patent implements a feedback mechanism where the receiving network element sends acknowledgment information back to the transmitting network element, containing the highest delivered PDCP sequence number and range information. This feedback enables the transmitter to track which packets have been successfully delivered and which require retransmission, thereby improving data delivery reliability through informed retransmission decisions.
Solution Approach 2:
The feedback information is segmented into specific components: highest delivered PDCP SN and range information. This segmentation allows the system to efficiently process feedback by breaking down the acknowledgment into manageable parts that can be easily parsed and acted upon, reducing processing complexity while maintaining reliability.
2Reliability
If all transmitted data is retransmitted to ensure delivery, then data delivery reliability is improved, but loss of time due to retransmission increases
Solution Approach 1:
The receiving network element provides feedback containing the highest delivered PDCP sequence number and range information, enabling the transmitting network element to identify exactly which packets have been successfully received. This feedback mechanism prevents unnecessary retransmission of already-delivered packets, reducing time loss while maintaining delivery reliability.
Solution Approach 2:
Instead of retransmitting all transmitted data, the system performs partial retransmission by sending only the specific packets that were not successfully delivered. This partial action approach minimizes retransmission time while ensuring that all necessary data is eventually delivered, resolving the contradiction between reliability and time loss.
3Device complexity
If out-of-order packets are handled without comprehensive feedback, then device complexity is reduced, but measurement precision of delivery status deteriorates
Solution Approach 1:
The feedback mechanism provides precise delivery status information by including the highest delivered PDCP sequence number and range information. This feedback enables the transmitting network element to accurately determine which packets have been delivered and which require retransmission, achieving high measurement precision of delivery status.
Solution Approach 2:
The patent replaces complex mechanical tracking systems with a streamlined feedback message structure that conveys delivery status information efficiently. By substituting detailed packet-by-packet tracking with a consolidated feedback message containing highest SN and range information, the system reduces processing complexity while maintaining accurate delivery status measurement.
4Reliability
If memory is retained for all transmitted data to ensure retransmission capability, then data delivery reliability is improved, but loss of substance in terms of memory resources increases
Solution Approach 1:
The feedback mechanism containing highest delivered PDCP SN and range information enables the transmitting network element to identify which packets have been successfully delivered. Based on this feedback, the system can selectively delete already-delivered data from memory while retaining only the packets that require potential retransmission, thus reducing memory resource consumption while maintaining retransmission capability.
Solution Approach 2:
The system discards (deletes) data that has been confirmed as successfully delivered based on feedback information, and recovers (retains) only the necessary data that may require retransmission. This selective discarding and recovering process optimizes memory resource utilization while ensuring that retransmission capability is maintained for undelivered packets.
Data Source
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AI summary
Methods, systems, and devices related to related to digital wireless communication, and more specifically, to techniques related to transmitting data and feedback data between network elements is disclosed. In one exemplary aspect, a method for wireless communication includes transmitting data from a first network element to a second network element. The method also includes receiving, at the first network element, feedback data from the second network element, where the feedback data includes a highest delivered packet data convergence protocol (PDCP) sequence number (SN) and information indicative of a range of data that has been successfully delivered to a terminal. The method also includes retransmitting at least a portion of the data from the first network element based on the feedback data.